1. Field of the Invention
This invention relates to a magneto-generator which is driven by an internal combustion engine.
2. Brief Description of Prior Art
As disclosed in Japanese Laid-Open Utility Model Application No. 55-53973, magneto-generators of this sort are generally constructed in such a manner as to accommodate within an iron cup rotor a stator core mounting power-generating coil windings and a signal generator.
However, in order to obtain large output by such a magneto-generator construction, a larger stator core with the power-generating coil windings has to be located within the iron cup rotor, which is therefore required to be of a larger size, resulting in an unduly large construction as a whole.
On the other hand, as proposed in Japanese Utility Model Publication No. 35-8321 and German Patent No. 885180, it is known to locate a stator core with power-generating coil winding on the outer side of a rotor. In magneto-generator constructions of this type, a crankshaft of an internal combustion engine is extended through a rotor, and a signal generator which is located in an axially protruded position relative to the rotor is operated by the crankshaft portion which is projected out of the rotor. Accordingly, the magneto-generators have a large axial length and lack compactness.
Further, Japanese Utility Model Publication No. 58-5094 proposes an arrangement in which a signal generator is positioned opposingly to a projection provided on the outer periphery of an iron cup, or alternatively a signal generator is formed integrally with a stator core at a position opposing the outer periphery of a crankshaft.
In a case where a signal generator is located on the outer periphery of an iron cup, however, it becomes necessary to provide an additional space for the signal generator at the sacrifice of compactness in construction. Where a signal generator is located in vis-a-vis relation with the outer periphery of a crankshaft by the use of the space between an iron cup and the crankshaft by the use of the space between an iron cup and the crankshaft, the shapes of the stator core and signal generator are restricted to certain designs.